Reading that so many users like myself make Veeam backups to Readynas units, I was wondering if anyone has looked at the merits of Veeam's replication features as opposed to Readynas Replicate.

I think they are different mechanisms to acheive different goals. I like Veeam Replication to replicate VMs to other hosts for quick disaster recovery. Also replicas would be kept for a shorter amount of time. Veeam backup would be used for longer term backups. I'd backup to the ReadyNas and then use ReadyNas replicate to move those backups offsite.

Veeam has a lot more "intelligence" that the ReadyNAS does. ReadyNAS just using RSYNC (which is awesome) to do a NAS to NAS replication. If the file in question is static and/or not open for writing, this will work great.

But typically that is not an option for virtualization (assumed from the use of Veeam) so in that case you cannot use "blind" replication from the NAS or SAN device (not a Netgear limitation, this is a standard storage limitation) and you must use replication with intelligence from the VM platform (Veeam in this case has that as it talks to the VM host.)

The backup software replicating its own backups will have taken into account situations when the replication stops(for whatever reason), recovery points are merged at production site and also possibility provide different backup retention at each site.

If Readynas is used, these cases have to be fully tested, especially with replication being stoped and restarted and also restorability during merge to understand when its safe to restore.